Schedule is honestly usually just based on what is convenient for the person. I see nothing wrong with three times a day.

I feed add ons with my dogs food daily and I started when they were pups (anything from raw meat, veggies, tinned sardines, boiled eggs). The only advice I have is to make sure no more than 25% of her daily calories come from added food, that is the guideline my vet set for me. Otherwise you have to make sure your add ons are also complete and balanced. I also would not try adding all kinds of foods at once. Add one thing for a few days and see how she takes to it. If you start adding all kinds of stuff at once and her stomach does not agree with something, you won’t know which food she is reacting to.

We do not have that kibble brand here so I cannot comment on whether it is good or not as I am not familiar with it. For puppy food, I do like Farmina puppy, Annamaet puppy, and Victor puppy